1. Field of the Invention
The present invention relates in general to a golf swing plane training device, and more particularly to a golf swing plane training device that comprises a rotating swing plane guide, one end pivotably connected to a golf club shaft, for constraining and controlling the swing arc of the golf club shaft when swung by a golfer to ingrain the feel of swinging on plane and consequently develop a correct golf swing.
2. General Background
Golf is a sport that has a centuries-long history and has been studied exhaustively by devoted golfers in their quest to understand and master the fundamentals of the golf swing mechanics. There is a constant stream of instructions in the form of books, videos and magazine articles on various elements of the golf swing, such as grip, stance, posture, steps of the swing (backswing, downswing and follow-through) and swing plane. Likewise, there is also a steady flow of training devices being created to help golfers tackle specific aspects of the golf swing. Of all the elements, the concept of the swing plane may possibly be the most complicated to grasp.
It is generally acknowledged that one must swing “on plane” to produce a good golf shot. However, many golfers do not have a clear understanding of what the swing plane is and what it is that should be on this plane. The primary reason for this difficulty is that a golf swing is a dynamic motion in a three-dimensional space that lasts only a second or two. It is infeasible for a golfer to observe or check his/her own swing plane in real time; the viewing of one's own swing can only be done using high-speed video or sequence photograph that captures the swing in a two-dimensional space. Furthermore, other referential concepts intended to help golfers gain understanding may be misinterpreted by some. For instance, there is the “shaft plane”, defined as the imaginary line that runs through the club shaft as it sits at address, and the “Hogan plane”, which is an imaginary pane of glass extending from the ball to the golfer's shoulders. Conceptual planes like these serve as valuable checkpoints of a golfer's swing at discrete steps; however, they do not describe the plane the club travels on throughout a golf swing.
Put simply, a correct golf swing requires the club shaft be swung on substantially the same plane on both the backswing and the downswing. If one could observe the trail of a marker on the club shaft made during a swing, it would correspond to an elliptical arc. The arc is not circular as the golfer does not pivot around a central point through the entire swing. Hips, arms, elbows, wrists, etc. are all pivot points that are activated at different moments during the swing. Also, this elliptical arc flattens further as the swing approaches the end of the backswing, i.e., the top of the swing. Furthermore, as the downswing is initiated with a slight lower-body shift toward the target coupled with a lowering of the right shoulder and elbow (for a right-handed golfer), the elliptical arc of the downswing, if it could be observed, would be narrower than that of the backswing and likely on a slightly flatter plane. Therefore, a correct golf swing requires the downswing be on the same plane as, or a slightly flatter plane than, that of the backswing. For a normal golf shot, when the golfer is not attempting to shape the ball flight, the downswing should not be on a steeper plane than that of the backswing, which tends to lead to the dreaded “outside-in” move not conducive to a good golf shot.
Finally, there is not a singular “ideal” swing plane that is suitable for all golfers. The plane angle, which is the angle between the swing plane and the ground, varies amongst golfers depending on many factors such as height, body build, arm length proportion, spine tilt at address, etc. Additionally, for each golfer, the plane angle also varies depending on the length of the particular club being used for a golf shot and the position of the ball, i.e., the lie. As to the arc of the swing, it should be narrower on the downswing. However, the degree again differs amongst golfers depending on factors such as the amount of lower-body forward shift, ability to retain a full wrist cock on the downswing, etc. These are natural and perfectly acceptable variations; there is no singular ideal swing that all golfers should be forced to imitate.
Perhaps to a greater extent than other aspects of the golf swing, the golfer must rely on the proper feel, or muscle memory, to keep his/her swing on plane. Even with a sound understanding of the concept, it is difficult for a golfer to work on his/her swing plane without the assistance of an instructor or a training device. Many training devices have been conceived over the years to help golfers “groove” their swing and develop the desired muscle memory. These devices fall generally into three categories. One category of training devices concentrate on constant- or variable-force resistance training of the specific muscles involved in the golf swing (backswing, downswing or follow-through), and secondarily on swing plane training. Most of these devices employ a handle connected to a flexible cord which, in turn, is connected to a resistance mechanism. The resistance force discourages, but not constrains, the user from making an abrupt, jerky movement when transitioning from backswing to downswing. Also, the flexible cord exerts little control over the path of the movement of hands or the swing plane. A second category of training devices use tracks or rails to lay out a predetermined, fixed path for a real or simulated golf club. Some devices mandate the exact same plane for both the backswing and the downswing. Others construct a narrower or flatter, but fixed and non-adjustable, path for the downswing. That is to say, most of these devices do not take into account the perfectly allowable variations in golfers' swings. Also, these devices are outsized, difficult to transport, and tend to be expensive to manufacture.
A third category of training devices employ a rotating swing arm, typically a rod, which constrains and guides the motion of a real or simulated golf club. Some also include a resistance mechanism for muscle strength training. The present invention fits in this general category. Examples include: U.S. Pat. No. 2,737,432, G. M. T. Jenks; U.S. Pat. No. 3,429,571, R. Abel, Jr.; U.S. Pat. No. 3,604,712, A. P. Lansing, et at.; U.S. Pat. No. 3,614,108, E. Garten; U.S. Pat. No. 4,261,573, R. H. A. Richards; U.S. Pat. No. 4,449,708, M. N. R. Humphrey; U.S. Pat. No. 4,486,020, B. T. Kane, et al.; U.S. Pat. No. 4,580,786, B. E. Shipley; U.S. Pat. No. 4,653,757, K. E. Wilkinson; U.S. Pat. No. 5,125,882, T. A. La Mothe, et al.; and U.S. Pat. No. 5,242,344, K. W. Hundley. While these devices take a similar approach as the present invention, each has one or more of the following drawbacks. (1) The device comprises a rotating rod fixedly connected to a club shaft, restricting the club shaft to move along the same circular arc on both the backswing and the downswing. As the golf swing does not naturally follow a circular arc, the device restricts the golfer from getting full extension in the middle of the backswing and forces the golfer to lift the club or swing around his/her body toward the top of the swing. (2) The club shaft is restricted to move only on the same swing plane throughout the swing. This forces some golfers to unnecessarily alter their swing. (3) The distal end of the rod not connected to the club shaft is anchored on a vertical support; the rod freely rotates or pivots relative to the anchor. No means is provided to adjust the angle of the swing plane. (4) The rotating swing arm is a flexible tension member or a telescoping rod that does not restrict the club shaft from moving on a steeper swing plane on the downswing. (5) Dissimilar shapes are involved where the club shaft is attached to the rotating rod, creating friction and hampering smooth motion transmission. For instance, the square clubface is attached to a telescoping rod, or the tapered club shaft is fastened with a ring nut. (6) The device does not allow the user to make a full swing as the rod would not clear his/her head. (7) The device is too complicated or too expensive to manufacture to be economically viable. (8) The device is outsized or requires being anchored on an opposing wall, thus is not transportable.
There exists a need for a golf swing plane training device which comprises a rotating swing plane guide, one end pivotably connected to a golf club shaft, for constraining and controlling the swing arc which is asymmetrically elliptical, while allowing for natural variations in golfers' swings but restricting improper swing plane changes.